1. Field of Invention
The present invention relates to a wavelength multiplexing on-chip interconnection circuit, an electro-optical device, and an electronic apparatus.
2. Description of Related Art
LSIs (Large Scale Integrated circuits) have progressed as integrated circuits having specific functions, such as DRAM (Dynamic Random Access Memory) or MPU (Micro Processing Unit), but with the speedup of MPUs, SRAMs (Static Random Access Memories), used as high-speed cache memories, there has been increased integration on the same chip. Now, by integrating flash memory, DSP (Digital Signal Processor), DRAM, etc. on one chip, the LSIs are being developed into high-performance information processing systems.
The LSI obtained by forming the integrated circuits having different functions on the same chip as described above is referred to as SOC (System On a Chip). In the SOC, the integrated circuits (circuit blocks) having different functions are two-dimensionally formed on one chip, and the respective circuit blocks are connected to each other through electrical wiring, referred to as global wiring. An operating speed of the SOC is restricted by problems, such as the signal delay or the increase in power consumption of the global wiring.
If signal transmission between the respective circuit blocks can be performed using optical signals, the signal delay or the increase in power consumption generated in the electrical global wiring can be reduced or avoided, thereby remarkably enhancing the processing speed of LSI.
Then, in order to transmit data using the optical signals, optical transmission devices for transmitting the optical signals emitted from a light source to a predetermined place and inputting the optical signals to light receiving elements, etc. are required. In the related art, optical fibers or optical waveguides formed on a substrate were used as optical transmission devices.
However, when the optical fiber is used as an optical transmission device, connection to optical components, such as a light emitting element and a light receiving element is complicated. There are problems that manufacturing is expensive and time consuming and miniaturization of the optical transmission device is difficult.
It can be considered that the connection of an optical transmission medium to the light emitting element and the light receiving element is simplified using an optical waveguide formed on a substrate. However, input/output structures suitable for the optical waveguide are not available, and the optical transmission device with fineness and facilitation of manufacture enough to apply to the integrated circuits is not developed yet.